Ofatumumab, the first human anti-CD20 monoclonal antibody for the treatment of B cell hematologic malignancies

Update in Diagnosis and Management of Primary Cutaneous B-Cell Lymphomas

Primary cutaneous lymphomas are a rare group of diseases, with an estimated incidence of 0.5-1 case per 100,000 people per year. Primary cutaneous B-cell lymphomas (pCBCLs) represent 25-30% of all primary cutaneous lymphomas. There are three main subtypes of pCBCL: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. Cutaneous B-cell lymphomas have a broad spectrum of clinical presentations, which makes diagnostic and therapeutic strategies challenging. To date, treatment recommendations for cutaneous B-cell lymphomas have been largely based on small retrospective studies and institutional experience. Recently, the pharmacotherapeutic landscape has expanded to include drugs that may modify the underlying disease pathology of pCBCLs, representing new therapeutic modalities for this rare group of diseases. Novel therapies used for other systemic B-cell lymphomas show promise for the treatment of pCBCLs and are being increasingly considered. These new therapies are divided into five main groups: monoclonal antibodies, immune checkpoint inhibitors, small-molecule inhibitors, bispecific T-cell engaging, and chimeric antigen receptor T cell. In this review, we discuss the clinical, histopathological, molecular, and cytogenetic features of the most common pCBCL subtypes with a focus on current and innovative therapeutic developments in their management. These emerging treatment strategies for B-cell lymphomas and cutaneous B-cell lymphomas may represent novel first-line options for the management of these rare diseases.

Efficacy and safety of ofatumumab and bendamustine followed by ofatumumab maintenance in patients with relapsed indolent non-Hodgkin lymphoma after prior rituximab

In indolent non-Hodgkin's lymphoma (iNHL), patients treated with rituximab, alone or in combination with various chemotherapeutic agents eventually relapse. This study evaluated the combination of ofatumumab and bendamustine, followed by maintenance ofatumumab in patients with relapsed iNHL with prior sensitivity to rituximab. Among the 49 patients enrolled, 24.5% achieved a complete response (CR) and 42.9% achieved a partial response (PR), with an overall response rate of 67.3% at the end of the induction therapy. Additionally, six patients with PR during induction phase achieved CR during the maintenance phase. Treatment-related adverse event was observed in 95.9% patients. The most common hematologic and biochemical abnormalities were decrease in lymphocytes (85.7%) and increase in glucose (91.8%), respectively. Overall, 42.9% progressed and 14.3% died during the study. Thus, ofatumumab in combination with bendamustine, followed by ofatumumab maintenance, was effective in the treatment of patients with iNHL with a manageable safety profile (NCT01294579).

Prognostic and predictive role of gene mutations in chronic lymphocytic leukemia: results from the pivotal phase III study COMPLEMENT1

Next generation sequencing studies in Chronic lymphocytic leukemia (CLL) have revealed novel genetic variants that have been associated with disease characteristics and outcome. The aim of this study was to evaluate the prognostic value of recurrent molecular abnormalities in patients with CLL. Therefore, we assessed their incidences and associations with other clinical and genetic markers in the prospective multicenter COMPLEMENT1 trial (treatment naive patients not eligible for intensive treatment randomized to chlorambucil (CHL) vs. ofatumumab-CHL (O-CHL)). Baseline samples were available from 383 patients (85.6%) representative of the total trial cohort. Mutations were analyzed by amplicon-based targeted next generation sequencing (tNGS). In 52.2% of patients we found at least one mutation and the incidence was highest in NOTCH1 (17.0%), followed by SF3B1 (14.1%), ATM (11.7%), TP53 (10.2%), POT1 (7.0%), RPS15 (4.4%), FBXW7 (3.4%), MYD88 (2.6%) and BIRC3 (2.3%). While most mutations lacked prognostic significance, TP53 (HR2.02,p<0.01), SF3B1 (HR1.66,p=0.01) and NOTCH1 (HR1.39,p=0.03) were associated with inferior PFS in univariate analysis. Multivariate analysis confirmed the independent prognostic role of TP53 for PFS (HR1.71,p=0.04) and OS (HR2.78,p=0.02) and of SF3B1 for PFS only (HR1.52,p=0.02). Notably, NOTCH1 mutation status separates patients with a strong and a weak benefit from ofatumumab addition to CHL (NOTCH1wt:HR0.50,p<0.01, NOTCH1mut:HR0.81,p=0.45). In summary, TP53 and SF3B1 were confirmed as independent prognostic and NOTCH1 as a predictive factor for reduced ofatumumab efficacy in a randomized chemo (immune)therapy CLL trial. These results validate NGS-based mutation analysis in a multicenter trial and provide a basis for expanding molecular testing in the prognostic workup of patients with CLL. ClinicalTrials.gov registration number: NCT00748189.

Diagnosis and Treatment of Primary Cutaneous B-Cell Lymphomas: State of the Art and Perspectives

Primary cutaneous B-cell lymphomas are rare entities that develop primarily in the skin. They constitute a heterogeneous group that represents around a quarter of primary cutaneous lymphomas. The 2018 update of the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification differentiates primary cutaneous marginal zone lymphoma and primary cutaneous follicle center lymphoma with an indolent course from primary cutaneous diffuse large B-cell lymphoma, leg type with an aggressive behavior. The broad spectrum of clinical presentations and the disease course marked by frequent relapses are diagnostic and therapeutic challenges. The classification of these diseases has been refined in recent years, which allows to better define their immunopathogenesis and specific management. In the present article, we review the main clinico-biological characteristics and the current therapeutic options of these three main subsets. Based on the recent therapeutic advances in nodal B-cell lymphomas, we focus on the development of novel treatment options applicable to primary cutaneous B-cell lymphomas, including targeted therapies, combination treatments and immunotherapeutic approaches, and cover basic, translational and clinical aspects aiming to improve the treatment of cutaneous B-cell lymphomas.

[Cutaneous lymphomas : Clinical presentation - diagnosis - treatment]

Cutaneous lymphomas comprise different subgroups with distinct biological behavior. Mycosis fungoides, the most common cutaneous lymphoma, presents with patches, plaques, tumors and erythroderma. Therapeutic options depend on stage and comprise local skin-directed treatment in early stages, while later stages and Sézary syndrome require systemic therapies including bexarotene, interferon or brentuximab vedotin. While the rare CD4-positive lymphoproliferation and acral CD8-positive lymphoma present with an invariably indolent course, cutaneous peripheral T‑cell lymphomas exhibit an aggressive clinical behavior. Among the subgroup of cutaneous B‑cell lymphomas, primary cutaneous marginal zone lymphoma and follicle center cell lymphoma belong to indolent entities with almost unrestricted overall survival, whereas cutaneous large B‑cell lymphoma presents with a significant risk of systemic dissemination and is associated with high lethality.

[Cutaneous lymphomas : Clinical presentation - diagnosis - treatment]

Cutaneous lymphomas comprise different subgroups with distinct biological behavior. Mycosis fungoides, the most common cutaneous lymphoma, presents with patches, plaques, tumors and erythroderma. Therapeutic options depend on stage and comprise local skin-directed treatment in early stages, while later stages and Sézary syndrome require systemic therapies including bexarotene, interferon or brentuximab vedotin. While the rare CD4-positive lymphoproliferation and acral CD8-positive lymphoma present with an invariably indolent course, cutaneous peripheral T‑cell lymphomas exhibit an aggressive clinical behavior. Among the subgroup of cutaneous B‑cell lymphomas, primary cutaneous marginal zone lymphoma and follicle center cell lymphoma belong to indolent entities with almost unrestricted overall survival, whereas cutaneous large B‑cell lymphoma presents with a significant risk of systemic dissemination and is associated with high lethality.

From Biology to Therapy: The CLL Success Story

Chemoimmunotherapy has been the standard of care for patients with chronic lymphocytic leukemia (CLL) over the last decade. Advances in monoclonal antibody technology have resulted in the development of newer generations of anti-CD20 antibodies with improved therapeutic effectiveness. In parallel, our knowledge about the distinctive biological characteristics of CLL has progressively deepened and has revealed the importance of B-cell receptor (BCR) signaling and upregulated antiapoptotic proteins for survival and expansion of malignant cell clones. This knowledge provided the basis for development of novel targeted agents that revolutionized treatment of CLL. Ibrutinib and idelalisib inhibit the Bruton tyrosine kinase (BTK) and phosphoinositide 3-kinase (PI3K) delta, respectively, thus interfering with supportive signals coming from the microenvironment via the BCR. These drugs induce egress of CLL cells from secondary lymphoid organs and remarkably improve clinical outcomes, especially for patients with unmutated immunoglobulin heavy-chain genes or with p53 abnormalities that do not benefit from classical treatment schemes. Latest clinical trial results have established ibrutinib with or without anti-CD20 antibodies as the preferred first-line treatment for most CLL patients, which will reduce the use of chemoimmunotherapy in the imminent future. Further advances are achieved with venetoclax, a BH3-mimetic that specifically inhibits the antiapoptotic B-cell lymphoma 2 protein and thus causes rapid apoptosis of CLL cells, which translates into deep and prolonged clinical responses including high rates of minimal residual disease negativity. This review summarizes recent advances in the development of targeted CLL therapies, including new combination schemes, novel BTK and PI3K inhibitors, spleen tyrosine kinase inhibitors, immunomodulatory drugs, and cellular immunotherapy.

Consequences of B-cell-depleting therapy: hypogammaglobulinemia and impaired B-cell reconstitution

Rituximab is a chimeric monoclonal antibody used to treat hematologic and autoimmune diseases by depleting CD20-expressing B cells. Patients may develop hypogammaglobulinemia following treatment, with some demonstrating failure of B-cell recovery. The true frequency of hypogammaglobulinemia and/or impaired B-cell reconstitution post rituximab is unknown due to the lack of prospective studies in different patient cohorts. The clinical significance remains controversial; some patients have recurrent infections while others are relatively asymptomatic. The aim of this review is to describe the prevalence of hypogammaglobulinemia and the associated risk for developing severe infection, in patients with differing underlying clinical conditions treated with rituximab. This may facilitate classification and prognostication of patients who develop these conditions and identify patients who may be at high risk of developing these complications, including those who may benefit from immunoglobulin replacement therapy.

Cutaneous B-cell lymphomas - pathogenesis, diagnostic workup, and therapy

Cutaneous B-cell lymphomas (CBCLs) comprise a group of mature lymphoproliferative B-cell disorders that primarily affect the skin. Characterized by great biological and clinical variability among its various subtypes, CBCLs fundamentally differ from primary nodal or systemic B-cell lymphomas. Given their uncomplicated course and excellent prognosis, lymphoma classifications rank primary cutaneous marginal zone lymphoma (PCMZL) and primary cutaneous follicle center lymphoma (PCFCL) as indolent CBCLs. By contrast, diffuse large B-cell lymphoma, leg type (DLBCL-LT) in particular, represent more aggressive lymphoma variants associated with a poorer prognosis. Therapeutic decisions and diagnostic procedures are based on the exact histological and immunohistochemical classification as well as the exclusion of systemic involvement and thus differentiation from nodal and systemic lymphomas. In this context, the diagnostic workup should also include molecular biology methods. Primary therapeutic options for indolent CBCL lesions include surgery and radiation therapy, as well as systemic treatment with rituximab (anti-CD20 antibody) in case of dissemination. More aggressive CBCLs usually require a combination of rituximab and polychemotherapy, primarily the CHOP regimen or modifications thereof. Given that the pathogenesis and biology of CBCLs has not been conclusively elucidated, and given the limited therapeutic armamentarium available, there is great need for comprehensive research, especially with respect to DLBCL-LT.

Monoclonal Antibody Therapies for Hematological Malignancies: Not Just Lineage-Specific Targets

Today, monoclonal antibodies (mAbs) are a widespread and necessary tool for biomedical science. In the hematological cancer field, since rituximab became the first mAb approved by the Food and Drug Administration for the treatment of B-cell malignancies, a number of effective mAbs targeting lineage-specific antigens (LSAs) have been successfully developed. Non-LSAs (NLSAs) are molecules that are not restricted to specific leukocyte subsets or tissues but play relevant pathogenic roles in blood cancers including the development, proliferation, survival, and refractoriness to therapy of tumor cells. In consequence, efforts to target NLSAs have resulted in a plethora of mAbs-marketed or in development-to achieve different goals like neutralizing oncogenic pathways, blocking tumor-related chemotactic pathways, mobilizing malignant cells from tumor microenvironment to peripheral blood, modulating immune-checkpoints, or delivering cytotoxic drugs into tumor cells. Here, we extensively review several novel mAbs directed against NLSAs undergoing clinical evaluation for treating hematological malignancies. The review focuses on the structure of these antibodies, proposed mechanisms of action, efficacy and safety profile in clinical studies, and their potential applications in the treatment of hematological malignancies.

[Treatment of indolent cutaneous B‑cell lymphoma]

Primary cutaneous B‑cell lymphomas are rarely encountered and represent 25% of all cutaneous lymphomas. Follicular B‑cell lymphoma and marginal zone lymphoma belong to indolent subtypes which as a rule have no systemic dissemination and, thus, a mostly unchanged life expectancy. Therefore, skin-directed treatment options such as excision or radiotherapy are usually sufficient to control the disease. In contrast, cutaneous diffuse large B‑cell lymphoma and EBV-associated B‑cell lymphomas of the skin belong to more aggressive entities which demand a systemic first-line upfront therapy with R‑CHOP. Nevertheless, mortality is still high and comparable to that of systemic/nodal large B‑cell lymphomas so that the identification of pathogenetic driver mutations or novel therapeutic targets may pave the way to better target-oriented therapies.

Monoclonal antibodies in the treatment of multiple sclerosis: emergence of B-cell-targeted therapies

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS, and one of the most common causes of disability in young adults. Over the last decade, new disease-modifying therapies have emerged, including monoclonal antibodies (mAbs) that provide highly targeted therapies with greater efficacy than platform therapies. In particular, monoclonal antibodies directed against CD20-positive B cells have shown remarkable results in recent clinical trials and renewed interest in the mechanism of B cell-depleting therapies to ameliorate relapse activity and progression in MS. Here, we review the mechanisms of action and clinical evidence of approved and emerging mAbs, with a focus on B cell-targeted therapies.

Current options to manage Waldenström's macroglobulinemia

INTRODUCTION

Waldenström's macroglobulinemia (WM) is a rare, incurable B-cell lymphoma, with a median survival of 5-10 years in symptomatic patients. There is no consensus on the standard of care and several agents are currently used in these patients. Areas covered: In this article, we will review the use of standard therapies and new drugs investigated such as monoclonal antibodies, proteasome inhibitors, immunomodulatory agents, Bruton's tyrosine kinase inhibitors and novel agents in early-stage development. Expert commentary: RCD (Rituximab/Cyclophosphamide/Dexamethasone) is an effective and safe treatment in first line in WM. BR (Bendamustine/Rituximab) or BRD (Bortezomib/Rituximab/Dexamethasone) provide durable responses, and are still indicated in most patients. Ibrutinib is a new option and it was approved as primary therapy and for relapse. Carfilzomib based therapy represents an emerging option for proteasome-inhibitor based therapy for WM. Despite encouraging results, WM remains an incurable disease; therefore, new treatment options are needed. For this reason, continued participation in clinical trials should be encouraged.

Monoclonal Antibodies for Relapsing Multiple Sclerosis: A Review of Recently Marketed and Late-Stage Agents

Treatment of multiple sclerosis (MS) has improved considerably over the last decade because of new insights into MS pathology and biotechnological advances. This has led to the development of new potent pharmaceutical compounds targeting different processes in the complex autoimmune pathology leading to chronic central nervous system (CNS) demyelination, neural loss, and, finally, neurological disability. Although a number of disease-modifying treatments are available for the treatment of the inflammatory phase of MS, there is still a need for highly efficacious therapies with an acceptable safety profile in order to gain therapeutic control early in the disease course. Monoclonal antibodies have proven to be some of the most efficacious disease-modifying therapies in the field of MS, and recent developments in clinical research hold promise for new compounds fulfilling the need for improved safety and high efficacy. We review recent developments in the field of therapeutic monoclonal antibodies used for the treatment of MS and current information on the mode of action, efficacy, and safety of existing and emerging therapeutic monoclonal antibodies as well as their place within the context of different treatment strategies. Finally, we consider the most important future developments.

Real-time Characterization of Antibody Binding to Receptors on Living Immune Cells

Understanding molecular interactions on immune cells is crucial for drug development to treat cancer and autoimmune diseases. When characterizing molecular interactions, the use of a relevant living model system is important, as processes such as receptor oligomerization and clustering can influence binding patterns. We developed a protocol to enable time-resolved analysis of ligand binding to receptors on living suspension cells. Different suspension cell lines and weakly adhering cells were tethered to Petri dishes with the help of a biomolecular anchor molecule, and antibody binding was analyzed using LigandTracer. The protocol and assay described in this report were used to characterize interactions involving eight cell lines. Experiments were successfully conducted in three different laboratories, demonstrating the robustness of the protocol. For various antibodies, affinities and kinetic rate constants were obtained for binding to CD20 on both Daudi and Ramos B-cells, the T-cell co-receptor CD3 on Jurkat cells, and the Fcγ receptor CD32 on transfected HEK293 cells, respectively. Analyzing the binding of Rituximab to B-cells resulted in an affinity of 0.7–0.9 nM, which is similar to values reported previously for living B-cells. However, we observed a heterogeneous behavior for Rituximab interacting with B-cells, which to our knowledge has not been described previously. The understanding of complex interactions will be facilitated with the possibility to characterize binding processes in real-time on living immune cells. This provides the chance to broaden the understanding of how binding kinetics relate to biological function.

B-Zell-Lymphome der Haut - Pathogenese, Diagnostik und Therapie

Primär kutane B-Zell-Lymphome (PCBCL) beschreiben reifzellige lymphoproliferative Erkrankungen der B-Zell-Reihe, die primär die Haut betreffen. Die Biologie und der klinische Verlauf der einzelnen PCBCL-Subtypen variieren untereinander stark und unterscheiden sich grundsätzlich von primär nodalen und systemischen B-Zell-Lymphomen. Primär kutane Marginalzonenlymphome (PCMZL) und primäre kutane follikuläre Keimzentrumslymphome (PCFCL) werden auf Grund ihres unkomplizierten Verlaufs und ihrer exzellenten Prognose zu den indolenten PCBCL gezählt. Demgegenüber stellen die diffus großzelligen B-Zell-Lymphome, hauptsächlich vom Beintyp (DLBCL, LT) die aggressiveren PCBCL-Varianten mit schlechterer Prognose dar. Für die Ausbreitungsdiagnostik und die Therapieentscheidung sind eine genaue histologische und immunhistochemische Klassifizierung sowie der Ausschluss einer systemischen Beteiligung in Abgrenzung zu nodalen oder systemischen Lymphomen notwendig. Die Diagnostik sollte dabei durch molekularbiologische Untersuchungen unterstützt werden. Therapeutisch stehen für die indolenten PCBCL primär operative und radioonkologische Maßnahmen im Vordergrund sowie eine Systemtherapie mit dem CD20-Antikörper Rituximab bei disseminiertem Befall. Die aggressiveren Varianten sollten in erster Linie mit Kombinationen aus Rituximab und Polychemotherapieschemata wie z. B. dem CHOP-Schema oder Modifikationen davon behandelt werden. Auf Grund der in allen seinen Einzelheiten noch nicht vollständig verstandenen Pathogenese und Biologie sowie des begrenzten Therapiespektrums der PCBCL besteht hier, speziell beim DLBCL, LT, noch erheblicher Forschungsbedarf.

Pharmacotherapeutic Management of Chronic Lymphocytic Leukaemia in Patients with Comorbidities: New Agents, New Hope

Chronic lymphocytic leukaemia (CLL) is mostly considered a disease of the elderly. As such, many patients present with comorbidities. Several scores allow for a qualitative and quantitative assessment of comorbidity in patients with CLL. Although our knowledge about the impact of comorbidity on outcomes in patients with CLL is still incomplete, it is becoming increasingly apparent that comorbidities could negatively interfere with CLL treatment. Recently, a number of new agents have been approved for use in patients with previously untreated CLL and comorbidities (i.e. obinutuzumab, ofatumumab), as well as in patients with previously treated or high-risk CLL (i.e. idelalisib, ibrutinib). This review discusses the role of comorbidity in patients with CLL, together with the changing treatment landscape for CLL in this patient population.

Obinutuzumab for the treatment of indolent lymphoma

Obinutuzumab is a humanized, type II anti-CD20 monoclonal antibody designed for strong induction of direct cell death and antibody-dependent cell-mediated cytotoxicity. The Phase III GADOLIN trial tested the clinical efficacy of obinutuzumab plus bendamustine followed by obinutuzumab monotherapy in rituximab-refractory indolent non-Hodgkin lymphoma versus treatment with bendamustine alone. It demonstrated significantly longer progression-free survival for the obinutuzumab-containing regimen in this difficult to treat patient group. Based on the results of this trial, US FDA approval was most recently granted for obinutuzumab in the treatment of follicular lymphoma that has relapsed after or was refractory to a rituximab-containing regimen. This article summarizes the available data on chemistry, pharmacokinetics, clinical efficacy and safety of obinutuzumab in the treatment of indolent non-Hodgkin lymphoma.

Waldenström's macroglobulinemia: a clinical perspective in the era of novel therapeutics

Waldenström's macroglobulinemia (WM) is a rare, low-grade malignancy with no established standard of care. Rituximab regimens are most commonly used, supported by their efficacy in hematologic malignancies, including WM. A growing number of investigational regimens for WM have been evaluated in phase II clinical trials, including single-agent and combination strategies that include newer-generation monoclonal antibodies (ofatumumab and alemtuzumab), proteasome inhibitors (bortezomib and carfilzomib), immunomodulatory agents (thalidomide and lenalidomide), phosphoinositide 3-kinase/protein kinase B (Akt)/mammalian target of rapamycin pathway inhibitors (everolimus and perifosene), a Bruton's tyrosine kinase inhibitor (ibrutinib), and a histone deacetylase inhibitor (panobinostat). Other novel agents are in early-stage development for WM. International treatment guidelines for WM suggest suitable regimens in the newly diagnosed and relapsed/refractory settings, in accordance with patient age, disease presentation, and efficacy and safety profiles of particular drugs. These factors must be considered when choosing appropriate therapy for individual patients with WM, to maximize response and prolong survival, while minimizing the risk of adverse events. This review article provides a clinical perspective of the modern management of patients with WM, in the context of available trial data for novel regimens and recently updated treatment guidelines.

The potential role for ocrelizumab in the treatment of multiple sclerosis: current evidence and future prospects

B cells play a central role in the pathogenesis in multiple sclerosis (MS), being involved in the activation of proinflammatory T cells, secretion of proinflammatory cytokines, and production of autoantibodies directed against myelin. Hence, the usage of B-cell-depleting monoclonal antibodies as therapy for autoimmune diseases including MS lay near at hand. Rituximab was the first therapeutic B-cell-depleting chimeric monoclonal antibody to be used successfully in MS. Ocrelizumab, a second-generation humanized anti-CD20 antibody, was explored in a large phase II, randomized, placebo-controlled multicentre trial in patients with relapsing-remitting disease. Compared with placebo, two doses of ocrelizumab (600 and 2000 mg on days 1 and 15) showed a pronounced effect on disease activity seen in magnetic resonance imaging (MRI) as gadolinium-enhanced lesions (89% and 96% relative reduction, both p < 0.001) and also had a significant effect on relapses. In exploratory analyses, both doses of ocrelizumab had better effect on gadolinium-enhanced lesions than interferon beta-1a intramuscularly that was used as a reference arm. Adverse effects were mainly infusion-related reactions, in particular during the first infusion. Serious infections occurred at similar rates in ocrelizumab and placebo-treated patients, and no opportunistic infections were reported. However, progressive multifocal leukoencephalopathy (PML) has been reported in patients treated with anti-CD20 monoclonal antibodies for other indications. Other anti-CD20 monoclonal antibodies have been tested as treatments for MS, including ofatumumab that has shown beneficial results in placebo-controlled phase II trials in patients with relapsing-remitting MS. Ocrelizumab is now in phase III development for the treatment of relapsing-remitting MS, as well as primary progressive MS, and the results of ongoing clinical trials are eagerly awaited and will determine the place of ocrelizumab in the armamentarium of MS therapies.

Antibody Therapies in Cancer

Antibody-based immunotherapy has become a standard treatment for a variety of cancers. Many well-developed antibodies disrupt signaling of various growth factor receptors for the treatment of a number of cancers by targeting surface antigens expressed on tumor cells. In recent years, a new family of antibodies is currently emerging in the clinic, which target immune cells rather than cancer cells. These immune-targeted therapies strive to augment antitumor immune responses by antagonizing immunosuppressive pathways or providing exogenous immune-activating stimuli, which have achieved dramatic results in several cancers. The future of cancer therapies is likely to combine these approaches with other treatments, including conventional therapies, to generate more effective treatments.

How immunoglobulin G antibodies kill target cells: revisiting an old paradigm

The capacity of immunoglobulin G (IgG) antibodies to eliminate virtually any target cell has resulted in the widespread introduction of cytotoxic antibodies into the clinic in settings of cancer therapy, autoimmunity, and transplantation, for example. More recently, it has become apparent that also the protection from viral infection via IgG antibodies may require cytotoxic effector functions, suggesting that antibody-dependent cellular cytotoxicity (ADCC) directed against malignant or virally infected cells is one of the most essential effector mechanisms triggered by IgG antibodies to protect the host. A detailed understanding of the underlying molecular and cellular pathways is critical, therefore, to make full use of this antibody effector function. Several studies over the last years have provided novel insights into the effector pathways and innate immune effector cells responsible for ADCC reactions. One of the most notable outcomes of many of these reports is that cells of the mononuclear phagocytic system rather than natural killer cells are critical for removal of IgG opsonized target cells in vivo.

Novel drug therapies in myeloid leukemia: a patent review

Both acute myeloid leukemia and chronic myeloid leukemia are thought to arise from a subpopulation of primitive cells, termed leukemic stem cells that share properties with somatic stem cells. Leukemic stem cells are capable of continued self-renewal, and are resistant to conventional chemotherapy and are considered to be responsible for disease relapse. In recent years, improved understanding of the underlying mechanisms of myeloid leukemia biology has led to the development of novel and targeted therapies. This review focuses on clinically relevant patent applications and their relevance within the known literature in two areas of prevailing therapeutic interest, namely monoclonal antibody therapy and small molecule inhibitors in disease-relevant signaling pathways.

Immunotherapy in pediatric malignancies: current status and future perspectives

Novel immune-based therapies are becoming available as additions to, and in some cases as alternatives to, the traditional treatment modalities such as chemotherapy, surgery and radiation that have improved outcomes for childhood cancer for decades. In this article, we will discuss what immunotherapies are being tested in the clinic, barriers to widespread application, and the future of immuno-oncology for childhood cancer. While in many cases, these therapies have shown dramatic responses in the setting of refractory or relapsed cancer, much remains to be learned about how to integrate these therapies into existing upfront regimens. The progress and challenges of developing immunotherapies for childhood cancer in a timely and cost-effective fashion will be discussed.

Pro-apoptotic effect of an anti-CD37 scFv-Fc fusion protein, in combination with the anti-CD20 antibody, ofatumumab, on tumour cells from B-cell malignancies

SMIP-016, a new anti-tumour agent, is a mouse/human chimeric fusion protein built on the ADAPTIR™ (modular protein therapeutic) platform targeting human CD37. In this study, for the first time, we examined pro-apoptotic activity of SMIP-016 in combination with monoclonal anti-CD20 antibody, ofatumumab (HuMax-CD20) in de novo chronic lymphocytic leukaemia (CLL) cells and in different B-cell neoplasm-derived lines. In CLL cells SMIP-016 exerted significant cytotoxicity (versus control - p=0.01). In the in vitro models, SMIP-016 was also distinctly active against Raji line (Burkitt lymphoma; BL) (versus control - p=0.007), Riva-1 line (diffuse large B-cell lymphoma; DLBCL) (versus control - p=0.002) and RPMI 8226 line (multiple myeloma cells; MM) (versus control - p=0.03). In studies combining SMIP-016 and ofatumumab, the cytotoxicity against CLL cells was significantly higher than the agents used alone (p<0.03). Remarkably enhanced cytotoxic activity of SMIP-016 and ofatumumab in combination was also observed in Raji and Riva-1 cell lines (p<0.01 and p<0.003, respectively). Importantly, both agents induced cytotoxicity at very low concentrations which suggests that potential side-effects may be decreased in clinical practice. The mechanism responsible for cytotoxicity of SMIP-016 in all the examined models was connected with caspase-dependent apoptosis. In majority of cell types SMIP-016 induced overexpression of Bax protein, as well as downregulation of Bcl-2, cIAP1 (p<0.03) and Smac/DIABLO (p<0.003) apoptosis-regulating proteins. In conclusion, our study demonstrated high pro-apoptotic activity of SMIP-016, especially in combination with ofatumumab, against ex vivo CLL cells, and BL or DLBCL in vitro cell lines. Thus, further preclinical studies in in vivo models are warranted, as this combination may be a promising therapeutic concept for treatment of those malignancies.

Therapeutic human monoclonal antibodies against cancer

There are over 30 monoclonal antibodies that are FDA approved for a variety of diseases ranging from malignancies to autoimmune diseases to macular degeneration. These antibodies include murine, fully humanized, and chimeric antibodies. There are a number of monoclonal antibodies used in the treatment of malignancies; in fact, three of the top five grossing antibodies (bevacizumab, trastuzumab, and rituximab) are used in oncology Scolnik (mAbs 1:179-184, 2009).

Immunotherapy treatments of warm autoimmune hemolytic anemia

Warm autoimmune hemolytic anemia (WAIHA) is one of four clinical types of autoimmune hemolytic anemia (AIHA), with the characteristics of autoantibodies maximally active at body temperature. It produces a variable anemia—sometimes mild and sometimes severe. With respect to the absence or presence of an underlying condition, WAIHA is either idiopathic (primary) or secondary, which determines the treatment strategies in practice. Conventional treatments include immune suppression with corticosteroids and, in some cases, splenectomy. In recent years, the number of clinical studies with monoclonal antibodies and immunosuppressants in the treatment of WAIHA increased as the knowledge of autoimmunity mechanisms extended. This thread of developing new tools of treating WAIHA is well exemplified with the success in using anti-CD20 monoclonal antibody, Rituximab. Following this success, other treatment methods based on the immune mechanisms of WAIHA have emerged. We reviewed these newly developed immunotherapy treatments here in order to provide the clinicians with more options in selecting the best therapy for patients with WAIHA, hoping to stimulate researchers to find more novel immunotherapy strategies.

Treatment challenges in the management of relapsed or refractory non-Hodgkin's lymphoma - novel and emerging therapies

Over the last few decades, advances in immunochemotherapy have led to dramatic improvement in the prognosis of non-Hodgkin's lymphoma (NHL). Despite these advances, relapsed and refractory disease represents a major treatment challenge. For both aggressive and indolent subtypes of NHL, there is no standard of care for salvage regimens, with prognosis after relapse remaining relatively poor. Nevertheless, there are multiple emerging classes of targeted therapies for relapsed/refractory disease, including monoclonal antibodies, antibody- drug conjugates, radioimmunotherapy, small-molecule inhibitors of cell-growth pathways, and novel chemotherapy agents. This review will discuss treatment challenges of NHL, current available salvage regimens for relapsed/refractory NHL, and the safety and efficacy of novel emerging therapies.

Novel agents and biomarkers for acute lymphoid leukemia

New genetic markers for adult acute lymphoblastic leukemia (ALL) have been found to have prognostic impact, such as the lymphoid transcription factor gene IKZF1 alterations, which are associated with a high rate of leukemic relapse in B-ALL. Although complete remission rates by induction chemotherapy in ALL are now high, the long-term survival is still disappointing. Improvements in the survival outcome of ALL have been observed in young adults as a result of the use of pediatric inspired regimens and the broadening of the number of patients who are eligible for allogeneic SCT. Development of new and less toxic agents also provide promise to improve the outcome in adult ALL, such as tyrosine kinase inhibitors in Ph-positive ALL, rituximab in CD20-positive disease, blinatumomab in precursor B-ALL and nelarabine in T-lineage ALL. Challenges for the future are to implement genomic profiling into the clinical setting to guide risk stratification and providing novel targets for tailored therapies.